Monday, March 6, 2017

When you send email to any internal users these will be routed based on user LegacyDN Exchange attributes and auto-complete cache in Microsoft Outlook and in Microsoft Outlook Web App (OWA) uses, these values to route email messages internally. If the value changes, the delivery of email messages may fail with a 5.1.1 NDR – Recipient is not found.

If someone changed any below object properties in Exchange or AD user LegacyExchangeDN will change,

First Name

Last Name

Email Address

Alias

Resolution: -

To resolve the email delivery issue, we need to convert the below IMCEAEX delivery address to X500 Address and add it on user Exchange properties under X500 Type.

Before you convert the values, we need to understand few things to make correct X500 address,